Demands are increasing in terms of attachability and shape following properties for devices and electrically conductive materials used in a variety of interfaces in the field of electronics, and especially sensors, displays and artificial skin for robots. Depending on the intended use, flexible devices require the ability to be disposed on curved surfaces or concavoconvex surfaces and to be freely deformed.
As an example of this type of electrically conductive material, films and glasses that use ITO have been widely used in the past as transparent electrically conductive materials for displays. However, such ITO films exhibit poor flexibility, undergo large changes in resistance as a result of deformations such as bending or stretching, and show a tendency to break. As a result, transparent electrically conductive films formed in a state whereby carbon nanotubes are highly dispersed in the film have been developed as flexible electrically conductive films (see Patent Documents 1 and 2).
Such electrically conductive films that use carbon nanotubes use plastic substrates such as PET films, and therefore exhibit excellent flexibility and can be molded to concavoconvex surfaces. However, substrates used in such electrically conductive films are not stretchable and cannot be said to be satisfactory in terms of attachability and ability to follow a variety of shapes.
In addition, electrically conductive films that use silver nanowires in the same way have been developed (see Patent Document 3), but there is no prior art that mentions the attachability and shape following properties of electrically conductive films that use silver nanowires, and for the same reasons as those given above, it is still the case that requirements relating to stretchability and shape following properties cannot be satisfied.